For the tin ceiling panels, those run about $20 a panel at the hardware stores. I actually found these PVC ones online (which are even BETTER because there is no rattling from the speakers!) and they were only $10 a panel. For the runners between them, we bought plain white (cheaper! :)and simply spray-painted them a darker color for a warm contrast. The ceiling is one of my favorite parts of the entire room!
For the "concession stand" area, it would've cost us quite a bit to do a "custom" job since the pre-existing cutout in the wall was an unusual depth - instead, we just bought standard cabinets and set them out about 6 inches from the wall - we still have plenty of storage space in them and no one would ever know there is just dead space behind them - an easy way to save some money!
We obviously contracted out some of the work (we are just not those people!) but we did what we could on our own. Taking care of all of the painting (not fun, but saved almost $2000 from an estimate we got!) was another way to cut costs.
So, from our "idea board" (we seriously started planning this before Pinterest existed, and we would cut out ideas from magazines and put them on a corkboard) and some heavy duty saving, we finally have an "entertainment room" that we couldn't love more. Which means... now I'm looking forward to my next house transformation project!!! (And I'm able to save up for that now by not having to pay for a babysitter anymore just so we can go to a movie! :)